Sinking foundations in Amsterdam

Wooden pilings and Foundation subsidence

Foundations built on wooden pilings may subside (gradually sink) for various reasons. The quality of the foundation and the shell of the building are recorded using foundation codes. The City of Amsterdam monitors foundation subsidence.

sinking foundations in Amsterdam

Since the ground beneath Amsterdam is very soft, many buildings in the city are built on wooden pilings. These wooden beams were pounded into a deeper layer of sand that is solid enough to bear the weight of a building. A stone foundation was built on top of those pilings.

As the wooden pilings age and deteriorate, a building may show signs of subsidence (sink slightly). Changes in groundwater level, soil compaction and soil accumulation can intensify subsidence. Sometimes there were not enough pilings used to build the foundation, or they were too short, too narrow, or the wood was poor quality.

 

Built before 1930

Buildings constructed before 1930 are more likely to have foundation problems. Most of these are located inside the A10 motorway ring. Since 1930, building codes and construction techniques have improved, and concrete was used more often.

 

cracks, skewing, rising damp

Subsidence leads to cracks, skewing, rising damp, and structural problems. Eventually, it can become dangerous and make a building unsafe to live in. If that happens, the building needs maintenance or the foundation needs to be repaired or replaced. That has already happened in many buildings in recent years.

gemeente-amsterdam-half

foundation codes

A foundation code (funderingscode) shows the quality of the building shell and the foundation. It also shows how soon the foundation will need to be repaired. Pay attention to this code when buying a home. A foundation code is always part of a foundation report.

There are four foundation codes:

Code 1: the quality is good. This is rare in foundations from before 1925.
Code 2: the quality is sufficient. The foundation will not require maintenance in the next 25 years. Minimal damage can be expected within that time.
Code 3: the quality is substandard. Minor damage can be expected within 10 to 15 years.
Code 4: the quality is insufficient. You will need to repair or replace the foundations immediately.
Pay particular attention to the date of the foundation study. The foundation may have deteriorated (more quickly) over time, so a new study might result in a different foundation code.

measuring bolts

In order to monitor subsidence, the City has placed measuring bolts in building façades in nearly all the neighbourhoods within the A10 motorway ring. These special bolts are used to take systematic measurements of subsidence and monitor progress closely.

Measuring bolt data on subsidence can be viewed online.

Zoom in to see the measuring bolt. Each point on the map is a measuring bolt; the colour shows the extent of the subsidence. Click on the dot to see the measurements for each bolt.

Foundation repairs

Repairing a foundation can be a major undertaking. Generally, it involves inserting new pilings to support the foundation, pushing them into the ground alongside the old foundation pilings.

foundations of monuments

In order to repair municipal monuments, you can apply for a low-interest loan from the Amsterdams Restauratiefonds (Amsterdam Restoration Fund).

For more information, please contact:

Gemeente Amsterdam
Monumenten en Archeologie
PO Box 10718
1001 ES Amsterdam
+31 (0) 20 251 4900
erfgoed@amsterdam.nl

F.A.Q.

Lorem ipsum dolor sit amet.

If you have commissioned a Building Survey then you can request this. We can only offer this by prior arrangement as we have to make sure the vendor is content for this to happen — sometimes they say no — and we also ask for payment before the survey. Please ask when you book your survey. We will give you a time to meet us, which will usually be towards the end of our survey. Any earlier and we won’t be able to tell you anything substantive — please note that we cannot do our job properly if you stay for the whole inspection as it is distracting and prevents us from giving you the best service. We find that usually around 20 minutes is enough for us to explain our findings to you.

The length of time the inspection takes is dependent on the size of the property and the extent of any defects that may be identified. For guidance, an inspection of a typical three-bedroom house in reasonable order may take several hours. Larger properties and properties with multiple defects will take more time. For very big houses two surveyors may work together.

We try, wherever possible, to dispatch our report a day or so after the inspection. Building surveys in particular are often 40 or 50 pages long and are all individually written so this takes time. If required, a brief verbal report can be made available upon receipt of payment.

We are confident in our abilities.

However, our surveys do have ‘get out’ clauses, but we do not hide behind them. Our surveys are always definitive. Basically, we’ll report on what we can see and not on what we can’t. We can’t guess, but we can give a considered opinion.

Our small print will be written clearly, is easy to understand and we stick by our quoted fee.

Check our Survey Terms and Conditions.

Absolutely not! A mortgage valuation is just that, a valuation of the property commissioned by your mortgage or loan lender, and written purely for their benefit to assess the risk of their loan against the resale value of the property.
A survey is written for you as the prospective buyer (or home owner), to give you the best possible assessment of the property’s condition, required repairs and maintenance, etc.